<p>"Boxing" is the process of putting a primitive value into a primitive-wrapper object. When that's done purely to use the wrapper class' <code>toString</code> method, it's a waste of memory and cycles because those methods are <code>static</code>, and can therefore be used without a class instance. Similarly, using the <code>static</code> method <code>valueOf</code> in the primitive-wrapper classes with a non-<code>String</code> argument should be avoided, as should concatenating empty string <code>""</code> to a primitive.</p>
<h2>Noncompliant Code Example</h2>

<pre>
int myInt = 4;
String myIntString = new Integer(myInt).toString(); // Noncompliant; creates &amp; discards an Integer object
myIntString = Integer.valueOf(myInt).toString(); // Noncompliant
myIntString = 4 + "";  // Noncompliant
</pre>
<h2>Compliant Solution</h2>

<pre>
int myInt = 4;
String myIntString = Integer.toString(myInt);
</pre>

